Kit for converting fluid fuel furnace to electric furnace



Oct. 18, 1966 FOLMAR 3,280,297

KIT FOR CONVERTING FLUID FUEL FURNACE TO ELECTRIC FURNACE Filed Dec. 13, 1963 2 Sheets-Sheet 1 Fig.

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United States Patent 3,280,297 KIT FOR CONVERTING FLUID FUEL FURNACE T0 ELECTRIC FURNACE Earl T. Folmar, P.0. Box 83, Goshen, Ala. Filed Dec. 13, 1963, Ser. No. 330,279 7 Claims. (Cl. 219 201 This invention relates to a novel and useful kit including components for converting a fluid fuel furnace to an electric furnace.

The kit of the instant invention is primarily adapted to convert an oil fired furnace to an electric furnace and includes components which may be substituted for the oil burning unit of an oil fired furnace so as to convert the latter to an electric furnace.

The conversion kit of the instant invention includes a base and an insulative mount for an upstanding electrical resistance heater elemet and a pair of insulating tubes for insulatively passing a pair of conductors for the resistance type heating element through the combustion chamber of the converted furnace.

While the kit of the instant invention comprises components which are to replace only the fluid heating unit and which utilize the existing controls for the fluid fuel heating unit for controlling the electric furnace, in some instances it may be advisable to change the various heat responsive actuating and limiting switches for controlling the heating element and blower of the converted furnace.

The main object of this invention is to provide a conversion kit for converting a liquid fuel furnace to an electric furnace.

Still another object of this invention, in accordance with the immediately preceding object, is to provide a conversion kit including components that may be readily handled and installed by mechanics of average skill as opposed to being limited to installation by experts.

Another object of this invention is to provide a conversion kit including components which may be substituted for the liquid fuel burner of the furnace which is to be converted with a minimum amount of effort and with a minimum use of special tools.

Yet another object of this invention is to provide a conversion kit that may be readily produced by the use of readily available components.

A final object of this invention to be specifically enumerated herein is to provide a conversion kit in accordance with the preceding objects which will conform to conventional forms of manufacture, be of simple construction and easy to install so as to provide a device that will be economically feasible, long lasting and relatively trouble-free in operation.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIGURE 1 is a front elevational view of a previously liquid fuel fired furnace converted to an electrical furnace in accordance with the present invention;

FIGURE 2 is a side elevational view of the assembly illustrated in FIG. 1 as seen from the right side thereof and with portions thereof broken away and shown in section;

FIGURE 3 is a top plan view of the electrical resistance-type heating unit comprising the main portion of the electric heating assembly;

FIGURE 4 is a vertical sectional view taken substan-v tially upon the plane indicated by the section line 44 of FIGURE 3;

FIGURE 5 is a vertical sectional view taken substantially upon the plane indicated by the section line 5-5 of FIGURE 3; and

FIGURE 6 is a top plan view of the base of the electric heating assembly.

Referring now more specifically to the drawings the numeral 10 generally designates a conventional form of furnace which was previously fired by liquid fuel and has been illustrated in the drawings as being inverted to an electric furnace in accordance with the present invention.

The furnace 10 includes an upstanding housing 12 and it may be seen from FIGURES 1 and 2 of the drawings that the housing 12 includes a swingable front door 14 which may be secured in the closed position by any suitable means and which provides a closure for a large opening 16 formed in the front wall 18 of the housing.

As a liquid fuel fired furnace the furnace 10 includes a centrally disposed upstanding combustion chamber 20 including intake louvers 22 formed in the upper portion of the front wall 18. The lower portion of the combustion chamber 20 comprises a combustion pot 24 which is supported from a horizontal support 26 and is laterally slidable to the left as viewed in FIGURE 2 of the draw ings outwardly of the front door 14 of the housing 12. In addition, the combustion chamber 20 includes an access opening 28 having a removable closure 30 therefor and the top wall 32 of the combustion chamber 20 has an opening 34 formed therein about which the lower end of a flue pipe (not shown) was secured, the portion of the line pipe above the lower end thereof passing through an opening 36 formed in the top wall 38 of the housing 12.

As a liquid fuel fired furnace, an electrically actuated carburetor was supported at the lower end of the combustion chamber 20 and was actuated electrically by means of a suitable source 40 of electrical potential. A room thermostat (not shown) is serially connected in a carburetor actuating circuit 42 including a conductor 44 extending from the source 40 to the room thermostat (not shown) and then upwardly through the housing 12 to a pair of heat limiters 46 and 48 which are serially connected to the conductor 44. The conductor 44 is then passed downwardly to the electrically actuated carburetor for actuating the latter. In addition, the furnace 10 includes a blower assembly generally referred to by the reference numeral 50 which is also electrically connected to the source 40 by means of a conductor 52 extending from the source 40 and up to a thermostatic 3 control switch 54 for initially actuating and subsequently terminating operation of the blower assembly 50 solely in response to the air temperature within the air passage 56 defined between the combustion chamber 20 and the hous ing 12. The conductor 52 therefore doubles back down from the switch 54 to the motor 60 of the blower assembly 50.

The conversion kit of the instant invention first includes a cover plate 62 which is secured to the top wall 32 in any convenient manner such as by fasteners 64 for closing the opening 34. In addition, a similar plate may be secured to the top wall 38 of the housing 12 in order to close the opening 36 if it is desired to do so. However, the opening 36 may act as an additional inlet opening for the air passage 56.

Then, the conversion kit includes a relay assembly of conventional design generally referred to by the reference numeral 66 which replaces the aforementioned car buretor and which is actuated by means of the circuit 42 to electrically connect the conductors 68 and 70, extending from a suitable high voltage source of electrical potential (not shown), to the flexible conductors 74 leading from the relay switch 66 to the electric heating assembly generally referred to by the reference numeral 76.

The electrical heating assembly 76 includes a base plate 78 having three depending legs 80, 82 and 84 of a plan 3 shape and size to be received within the pot 24 and supported from the support 26 with the legs 80, 82 and 84 maintaining the plate 78 in spaced relation to the support 26.

Two pairs of insulators 86 and 88 and 90 and 92 are supported from and project upwardly away from the plate 78 and have a pair of conductor and supporting bars 94 and 96 respectively supported therebetween. Each of the insulators 86, 88, 90 and 92 has a transverse opening 98 formed therethrough and a transverse groove 100 formed across its top. The conductor bars 94 and 96 include opposite end portions which are notched as at 102. Each of the notches 102 forms a pair of projections 104 and 106 on the corresponding end of the associated bar and each projection 106 is snugly received in the corresponding opening 98 and each projection 104 embracingly received in the corresponding notch or groove 100. In this manner, the bars 94 and 96 are supported in spaced relation relative to each other and to the plate 78 from the upper ends of the insulators 86, 88, 90 and 92.

The electric heating assembly further includes an upstanding electrical heater unit generally referred to by the reference numeral 110 and including a grooved insulator standard 112 and a double coil of resistance heating wire 114 whose opposite ends are secured to a pair of depending and bifurcated female conductors or terminals 116 and 118 which depend below an insulative base 120 carried by the standard 112. Each of the conductors 116 and 118 has a downwardly opening groove 122 formed therein which snugly receives the corresponding pair of vertically spaced and laterally projecting studs or projections 124 secured to the corresponding conductor bar.

The heating unit 110 may be electrically connected to the bars 94 and 96 by inserting the unit 110 through the access opening 28 after the pot 24 has been positioned in vertical alignment with the upper portion of the combustion chamber 20.

The leg 82 has a threaded bore 130 formed therein and a suitable fastener 132 is secured through an opening 134 formed in the side wall of the pot 24 and insulated from the pot 24 by means of a grommet 136. The fastener 132 is secured in the threaded bore 130 and thereby secures the base plate 78 and the heating element supported thereby within the combustion chamber 20. The conductors 72 and 74 each pass through a tubular insulating sleeve 140 which may be secured through an opening 142 formed in the side wall of the pot 24 in any convenient manner such as by asbestos tape (not shown).

The relay 66 is supported from a horizontal support 144 projecting laterally outwardly of an enclosure 146 for the blower assembly 50. In addition, the enclosure 146 supports a supplemental draft blower 148 which was utilized when the furnace was liquid fuel fired. The blower 148 may or may not be removed as desired when the furnace 10 is converted to electric heat.

The foregoing is consideredas illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. In combination with a fluid fuel furnace of the type including an upstanding combustion chamber having a flue opening at its upper end and a removable burner pot at its lower end, a kit for converting said furnace to electric heat, said kit comprising a base disposed in and supported from the bottom of said pot, insulator means. carried by said base and projecting upwardly therefrom and insulatively supporting a pair of conductors adapted to be connected to a suitable source of electrical potential, an upstanding electrical resistance heater element including a pair of lead-in conductors, said pairs of conductors including coacting means readily releasably engageable with each other for electrically connecting said heater element to and supporting said heating element solely from the first-mentioned pair of conductors.

2. The combination of claim 1 wherein said insulator means comprises two pairs of upstanding insulators, each of the first-mentioned conductors being supported from a corresponding pair of said insulators.

3. The combination of claim 1 wherein said coacting means include means releasably supporting said heating element from the first-mentioned pair of conductors upon downward movement of said heating element toward the second-mentioned pair of conductors.

4. The combination of claim 1 including a pair of insulative tubes secured through spaced portions of the sides of said pot and having a pair of electrical conductors passed therethrough for the purpose of electrically connecting the first-mentioned conductors to a source of electrical potential disposed exteriorly of said burner pot.

5. In combination with a fluid fuel furnace of the type including an upstanding combustion chamber having a flue opening at its upper end and a removable burner pot at its lower end, a kit for converting said furnace to electric heat, said kit comprising a base disposed in and supported from the bottom of said pot, insulator means carried by said base and projecting upwardly therefrom and insulatively supporting a pair of conductors adapted to be connected to a suitable source of electrical potential, an upstanding electrical resistance heater element including a pair of lead-in conductors, said pairs of conductors including coacting means readily releasably engageable with each other for electrically connecting said heater element to and supporting said heating element solely from the first-mentioned pair of conductors, said insulator means comprising two pairs of upstanding insulators, each of the first-mentioned conductors being supported from a corresponding pair of said insulators, each of said insulators having an opening formed therein, the openings of each pair of insulators opening generally toward each other, each of said first pair of conductors including a pair of generally oppositely directed projections received in the corresponding openings.

6. In combination with a fluid fuel furnace of the type including an upstanding combustion chamber having a flue opening at its upper end and a removable burner pot at its lower end, a kit for converting said furnace to electric heat, said kit comprising a base disposed in and supported from the bottom of said pot, insulator means carried by said base and projecting upwardly therefrom and insulatively supporting a pair of conductors adapted to be connected to a suitable source of electrical potential, an upstanding electrical resistance heater element including a pair of lead-in conductors, said pairs of conductors including coacting means readily releasably engageable with each other for electrically connecting said heater element to and supporting said heating element solely from the first-mentioned pair of conductors, said insulator means comprising two pairs of upstanding insulators, each of the first-mentioned conductors being supported from a corresponding pair of said insulators, each of said insulators having an opening formed therein, the openings of each pair of insulators opening generally toward each other, each of said first pair of conductors including a pair of generally oppositely directed projections received in the corresponding openings, the first-mentioned pair of conductors comprising a pair of generally parallel elongated bars extending between corresponding pairs of said insulators, the second pair of conductors projecting down wardly from the lower end of said heating element and releasably engageable with the first-mentioned pair of con- :29 ductors, the lower end of said heating element being supported from an insulative support of sufiicient plan area to span the distance between said bars and rest on the latter.

7. The combination of claim 6 wherein each of said bars includes a pair of laterally projecting vertically spaced projections, each of the second-mentioned contacts comprising a depending blade-like member having a downwardly opening slot formed in its lower end snugly receiving the corresponding pair of vertically spaced projections.

References ited by the Examiner UNITED STATES PATENTS Rice 219536 Hauser. Fisher. Bailey 219375 Powell.

RICHARD M. WOOD, Primary Examiner. C. L. ALBRITTON, Assistant Examiner. 

1. IN COMBINATION WITH A FLUID FUEL FURNACE OF THE TYPE INCLUDING AN UPSTANDING COMBUSTION CHAMBER HAVING A FLUE OPENING AT ITS UPPER END AND A REMOVABLE BURNER POT AT ITS LOWER END, A KIT FOR CONVERTING SAID FURNACE TO ELECTRIC HEAT, SAID KIT COMPRISING A BASE DISPOSED IN AND SUPPORTED FROM THE BOTTOM OF SAID POT, INSULATOR MEANS CARRIED BY SAID BASE AND PROJECTING UPWARDLY THEREFROM AND INSULATIVELY SUPPORTING A PAIR OF CONDUCTORS ADAPTED TO BE CONNECTED TO A SUITABLE SOURCE OF ELECTRICAL POTENTIAL, AN UPSTANDING ELECTRICAL RESISTANCE HEATER ELEMENT INCLUDING A PAIR OF LEAD-IN CONDUCTORS, SAID PAIRS OF CONDUCTORS INCLUDING COACTING MEANS READILY RELEASABLY ENGAGEABLE WITH EACH OTHER FOR ELECTRICALLY CONNECTING SAID HEATER ELEMENT TO AND SUPPORTING SAID HEATING ELEMENT SOLELY FROM THE FIRST-MENTIONED PAIR OF CONDUCTORS. 